1. Field of the Invention
The present invention relates to an isolation differential combiner and more particularly to an isolation network for plural antennas spaced apart from each other.
2. Description of the Prior Art
The concept of combining two spaced antennas with a delay line system to provide a cardioid pattern of reception or transmission is well known. In general, such systems provide a fixed delay on a non-differential basis so that the desired pattern is obtained but results in a frequency dependent system. Such systems have no provision for providing reciprocal patterns in opposing directions. The present invention overcomes the disadvantages of such systems in that it provides pattern formation with opposing cardioids available from separate output ports, and in addition, provides such patterns simultaneously without interaction and on a frequency independent basis.